You probably noticed how we, the audience, have a lot more information about what's happening on stage than the characters do. Case in point: throughout the play, we know the fairies use magic to play pranks and to make the bewildered characters fall in and out of love, but the lovers have no idea what's happened to them. This is a classic case of "dramatic irony" (when the audience knows more than the characters do so that the characters' words and actions have a different meaning for us than they do for the characters on stage). It's a technique Shakespeare uses for comedic effects throughout A Midsummer Night's Dream.
Let's look closely at another example from the play. In Act 3, Scene 1, Bottom's head is transformed into that of an "ass" (a.k.a. donkey). Bottom doesn't know what's happened to him, so he's really confused when his pals flip out and run away in fear. Bottom thinks he's being punked and, when he's left alone on stage, he complains to us: "I see their knavery. This is to make an ass of me, to / fright me, if they could" (3.1.16). Of course, when Bottom accuses his friends of trying to "make an ass" of him, it's funny to us because we know something that Bottom doesn't – he literally has been made into an ass. (Also, his name, "Bottom," becomes very fitting.)